This is Ayat Al-Kursi and tremendous virtues have been associated with it, for the authentic Hadith describes it as `the greatest Ayah in the Book of Allah.’

Imam Ahmad recorded that `Ubayy bin Ka`b said that the Prophet asked him about the greatest Ayah in the Book of Allah, and `Ubayy answered, “Allah and His Messenger know better.”
When the Prophet repeated his question several times,
`Ubayy said, “Ayat Al-Kursi.”
The Prophet commented,

MEANING:
The explanation of this Hadith is that such a person is guaranteed Jannah, Innshaa Allaah.
However, this applies as long as that particular person does not commit any major sin without seeking repentance for it. In such a case this guarantee will not apply.

‘Ali (RA) said:
”I heard the Prophet (صلى الله عليه وسلم) saying while on his pulpit:
‘Whoever reads Aayatul Kursi, (Quran 2:255), after each obligatory prayer,
there is nothing which prevents him from entering Paradise except death,
and it is only a righteous and pious worshipper who would persist in reciting it regularly.”
[Al-Bayhaqi]
Albaani classified it as authentic, and other scholars classified it as a sound narration

It is reported by at-Tabarani that the Prophet (صلى الله عليه وسلم) said:
“The one who recites Ayat-al kursi after the conclusion of an obligatory prayer, he is under the Care of Allah until the next prayer commences.”
[at-Tabaraani’s At Targheeb wat-Tarheeb (2:435)]

Sayyidina Abu Huraira (RA) reported that Allah’s Messenger (صلى الله عليه وسلم) said,
“Everything has a hump and the hump of the Quran is surah al-Baqarah. There is a verse in it that is the
chief of all verses of the Qur’an, the ayat ul-Kursi.”
(Tirmidhi 2887)

Abu Hurairah reports:
“Whenever you go to bed, recite “Ayat-al-Kursi”– ‘Allaahu laa ilaaha illaa huwal-Hayyul Qayyuum’ till you finish the whole verse. (If you do so), Allah will appoint a guard for you who will stay with you and no satan will come near you till morning. ”
(Bukhari Book #38, Hadith #505)

Abu Umamah (ra) reported that the Prophet (صلى الله عليه وسلم) said that the ismullahi al- a’dham (The Greatest Name of Allah), through which Allah assuredly fulfils people’s needs, is contained in three surahs in the Qur’an: al-Baqarah, Al Imran and Taha.
Abu Umamah (ra) says that when he searched for the ismullahi al- a’dham, he found it to be in Ayat al-kursi (2:255); and in Surah Al-’Imran (3:2); and in Surah Taha (20:111).
[al-Hakim, ibn Majah, at-Tabarani, at-Tahawi, and others]

If one recites this after performing Wudhoo, the 5th Imam Hadhrat Imam Muhammad Baqir (RA) has said: Allaah will give him a reward of 40 years of Ibadaat, his position will be raised in the Heavens 40 times (levels) and will marry him to 40 Horains.

Ash-Shawkaani, may Allaah have mercy on him, said: ‘The chain of narrators of this narration includes Muqaatil Ibn Sulaymaan, and he is a liar.

The supplication the prophet MuHammadur Rasoolullaah (Sollallaahu ‘Alayhi wa sallam) made for his Ummah

A’ishah (RA) narrated:

“Once, when I saw the Prophet (Sollallaahu ‘Alayhi wa sallam) in a good mood, I said to him:

“O Messenger of Allaah! Supplicate to Allaah for me!”

So, he (Sollallaahu ‘Alayhi wa sallam) said:

“O Allaah! Forgive ‘A’ishah her past and future sins, what she has hidden, as well as what she has made apparent.”

So, I began smiling, to the point that my head fell into my lap out of joy.

The Messenger of Allaah (Sollallaahu ‘Alayhi wa sallam) said to me:

“Does my supplication make you happy?”

I replied: “And how can your supplication not make me happy?”

He (Sollallaahu ‘Alayhi wa sallam) then said:

“By Allaah, it is the supplication that I make for my Ummah (Muslim Nation) in every prayer.”“
[Reported in ‘Sahih Mawarid adh-Dhaman’ (1875), and it is in ‘as-Silsilah as-Sahihah’ (2254)]

“O Allaah, Bestow upon MuHammad (Sollallaahu ‘Alayhi wa sallam) al-wasilah (a station in Paradise) and al-fadilah (a rank above the rest of creation) And raise him to the Maqamam Mahmud (the rank you have promised him) ”

“O Allaah! Give reward to our Hazrat MuHammad (Sollallaahu ‘Alayhi wa sallam) the reward which is benefitting as he deserves”.

Narrated AbuTha’labah al-Khushani:
AbuUmayyah ash-Sha’bani said:
I asked Abu Tha’labah al-Khushani: What is your opinion about the verse “Care for yourselves”.
He said: I swear by Allaah, I asked the one who was well informed about it;
I asked the Apostle of Allaah (صلى الله عليه وسلم) about it.

He (صلى الله عليه وسلم) said:
No, enjoin one another to do what is good and forbid one another to do what is evil.
But when you see niggardliness being obeyed, passion being followed, worldly interests being preferred, everyone being charmed with his opinion, then care for yourself, and leave alone what people in general are doing;

for ahead of you are days which will require endurance, in which showing endurance will be like grasping live coals.
The one who acts rightly during that period will have the reward of fifty men who act as he does.

Another version has:
He said (The hearers asked:) Apostle of Allaah (صلى الله عليه وسلم), the reward of fifty of them?
He (صلى الله عليه وسلم) replied:
The reward of fifty of you.
(Abu Dawood Book #37, Hadith #4327)

Narrated Abu Musa:
The Prophet (صلى الله …عليه وسلم) said,
“The example of Muslims, Jews and Christians is like the example of a man who employed laborers to work for him from morning till night for specific wages.

They worked till midday and then said,
‘We do not need your money which you have fixed for us and let whatever we have done be annulled.’

The man said to them,
‘Don’t quit the work, but complete the rest of it and take your full wages.’ But they refused and went away.

The man employed another batch after them and said to them, ‘Complete the rest of the day and yours will be the wages I had fixed for the first batch.’
So, they worked till the time of ‘Asr prayer. Then they said, “Let what we have done be annulled and keep the wages you have promised us for yourself.’

The man said to them, ‘Complete the rest of the work, as only a little of the day remains,’ but they refused.

Thereafter he employed another batch to work for the rest of the day and they worked for the rest of the day till the sunset, and they received the wages of the two former batches.

So, that was the example of those people (Muslims) and the example of this light (guidance) which they have accepted willingly.
(Muslim Book #36, Hadith #471)